Re: [SeattleRobotics] Re: Motion controls

I ve been seeing different people bouncing back and forth between using a power window motor and a solenoid. A power window motor is a bit large and the

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, Jun 11, 2011

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I've been seeing different people bouncing
back and forth between using a power window motor and a solenoid. A power
window motor is a bit large and the solenoid actuation is non-linear in force
applied. Another method is to use an automobile electric door lock
actuator. They look like solenoids but are actually very small
motor-driven linear actuators. The disadvantage is that they draw a lot of
current for their size- I'm guessing 5+ amps, and have a small 'throw.'
I've seen them surplus new for $5.00 or less.

Tom C.

My
thoughts would be a solenoid to rotate a cam / latch assy and another solenoid
to realise with a spring return. This should remove the power and heat
problems?

Gene

--- In SeattleRobotics@yahoogroups.com, "Lloyd
Moore" <moorel3@...> wrote:>> I was assuming the solenoid
would be driving a mechanical apparatus to get the rotation, although there
are rotational solenoids. Granted the force could be an issue, and that would
have to be looked at. Given this system is located on the rear bumper I
donâ€™t think the forces are going to be that high. The motor solution
mentioned would also work but is more complex. > >
> > I just did a REALLY fast search for solenoids on the web and
came across this page: http://www.generalcontrol.com/solenoid.htm >
> > > Iâ€™m not saying ANY of these are the correct
solution, but just looking at the general parameters here you have a range of
linear to 110 degrees of rotation, with forces up to 350 lbs in some cases.
(One of many pages â€" just search for â€œhigh force solenoidâ€ )Of course
you have to reduce the force by the stroke length and all of that, but I
suspect there is something out there that would work. Not having full drawings
and such of what is being built Iâ€™ll have to leave the specific search and
selection as an exercise to the reader. :-)> > >
> As for the cruise control I ran into this issue specifically when
converting to LED brake lights. In my specific case the cruise control system
sends a small sense current through the brake lights specifically when they
are off. If that current isnâ€™t within some expected range then the cruise
control would not engage. Different cars do this in different ways. Some use a
switch on the brake peddle and donâ€™t do this at all. My guidance here is to
simply be aware that some vehicles monitor the brake lights in various ways
for diagnostics. > > > > Thanks,>
> Lloyd Moore, > > President> >
> > > > www.CyberData-Robotics.com
<http://www.cyberdata-robotics.com/> > >
1.206.715.7628>
> > > > > This electronic mail
(including attachments) may contain information that is privileged,
confidential, and/or otherwise protected from disclosure to anyone other than
its intended recipient(s). Any dissemination or use of this electronic email
or its contents (including attachments) by persons other than the intended
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entirety. Thank you.> > > >
_____ > > From: SeattleRobotics@yahoogroups.com
[mailto:SeattleRobotics@yahoogroups.com] On Behalf Of David Buckley>
Sent: Saturday, June 11, 2011 4:25 PM> To:
SeattleRobotics@yahoogroups.com> Subject: Re: [SeattleRobotics] Re:
Motion controls> > > > >
> ï»¿ > > Lloyd> > From where are you
going to get a solenoid that big and powerful to operate a mechanism rotating
180deg?> > Especially one that will work from 12v.>
> If you managed to find a solenoid, seeing as when the brakes are off
the brake lights are off and the solenoid would be off how can there be a
problem with reactivating the cruise control?> > DAvid>
> > > ----- Original Message ----- >
> From: moorel3@... > > To:
SeattleRobotics@yahoogroups.com > > Cc:
SeattleRobotics@yahoogroups.com > > Sent: Saturday, June 11,
2011 11:35 PM> > Subject: Re: [SeattleRobotics] Re: Motion
controls> > > > >
> Jackson,> > Based on this information I would be really
leaning toward the solenoid solution. As was also mentioned you would want a
spring on this to close it when the power is removed. > >
Depending on the size of the solenoid you may also want to include a relay so
that you are not driving the entire electrical load directly from the brake
lights. Depending on the specific vehicle, altering the amount of current
going through the brake light circuit can affect other systems - the one that
comes to mind is the cruise control, many of them sense brake light current to
disable the cruise control, and will not allow the cruise control to activate
if the current appears to be out of range. > > If that general
idea works for you let me know and I can answer specific questions or give you
some more general guidance.> > Thanks,> Lloyd>
> > ----- Original Message -----> From: "jackson hennes"
<jacksonhennes@...>> To: SeattleRobotics@yahoogroups.com>
Sent: Saturday, June 11, 2011 12:55:53 PM> Subject: [SeattleRobotics]
Re: Motion controls> > > > Hello
everyone,> I want to thank you all for your efforts to help me solve
this problem. I have read each response and will do my best to provide the
information each person has requested.> > Peter, David, Lloyd,
Alan, Daniel, and Bill:> > The power supply will be from a car
brake light system. So it will be DC and only be powered when the brakes are
applied. The project needs to open when the brakes are applied and close when
the brakes are released. It will have to open under power and close without
power.> > I would like the opening process to be 3 seconds or
less if possible but that will depend on the cost of the device opening it. To
keep costs reasonable the activation time will have to be balanced with the
price of the system used to open it.> > The wind source will be
the moving car itself. The device will be located on or near the center of the
rear bumper which should protect it from much of the wind.> >
The panels that open like a tri-fold will be six inches by 12 inches, hinged
to the main section and will be made of plastic. This should lower the weight
but increase the strength of the panels.> > The turning project
will be about the size of a two liter bottle and will also be made of
plastic.> > My skill level in the mechanical area is above
average at least as I do my own home remodeling, auto mechanics, and any other
work you do in a home, including plumbing and wiring. As for electronics, I
have built my own computer by ordering the parts and assembling them. I have
not built my own board. I did solder a new fuse into a board, so I do have the
ability to put parts into a board. I wouldn't have a clue as to what the parts
of a board do to make the thing operate. If you tell me what board to use and
where to put the parts, I would be able to assemble it.> > I
hope this will allow you to give me the most accurate suggestions possible. I
greatly appreciate all you work and efforts on my behalf. > >
Sincerely,> Jackson Hennes> > --- In
SeattleRobotics@yahoogroups.com
<mailto:SeattleRobotics%40yahoogroups.com> , "Lloyd Moore"
<moorel3@> wrote:> >> > Jackson,> >
> > > > > > Could I get a bit more information
on what you are doing? I've got a couple> > ideas floating around
and depending on your specific skills, power> > requirements I'm not
sure which way to go. Let me throw them out there and> > let give me
some thoughts on each:> > > > > > > >
1. Simple solenoids - could be light weight and if all you have is a>
> two position, power on - power off requirement might be the simplest way
to> > go. Could be a bit power hungry though. > > 2. Small
/ micro servo motors. Likely the best solution overall, but is> >
also the most complex and expensive. This may also be overkill for what
you> > are trying to do.> > 3. Shape memory wire / Muscle
Wire - similar to solenoids but even> > lighter and simpler. This
would likely have the highest power requirements,> > but could also
be combined with a microcontroller to give additional> >
control.> > > > > > > >
Thoughts?> > > > > > > >
Thanks,> > > > Lloyd Moore, > > > >
President> > > > > > > > > >
> > www.CyberData-Robotics.com
<http://www.cyberdata-robotics.com/> > > > >
1.206.715.7628> > > > > > > > >
> > > This electronic mail (including attachments) may contain
information that is> > privileged, confidential, and/or otherwise
protected from disclosure to> > anyone other than its intended
recipient(s). Any dissemination or use of> > this electronic email
or its contents (including attachments) by persons> > other than the
intended recipient(s) is strictly prohibited. If you have> >
received this message in error, please notify us immediately by reply
email> > so that we may correct the situation. Please delete the
original message> > (including attachments) in its entirety. Thank
you.> > > > > > > > _____ >
> > > From: SeattleRobotics@yahoogroups.com
<mailto:SeattleRobotics%40yahoogroups.com> > >
[mailto:SeattleRobotics@yahoogroups.com
<mailto:SeattleRobotics%40yahoogroups.com> ] On Behalf Of
jacksonhennes> > Sent: Thursday, June 09, 2011 7:23 PM> >
To: SeattleRobotics@yahoogroups.com
<mailto:SeattleRobotics%40yahoogroups.com> > > Subject:
[SeattleRobotics] Motion controls> > > > > >
> > > > > > Hello Everyone,> >
> > I am trying to figure out an inexpensive way to make a couple
projects move.> > > > The first project needs to turn 180
degrees when power is applied and stay> > there until the power goes
off and return back to it's home position.> > > > The
second project needs to open a tri-fold mechanism so all the panels
are> > in the same plane when it is open and separate planes when
closed. The> > mechanism should be in the open position when power
is applied and close> > when the power is removed.> >
> > If anyone could help me on low cost ideas to make these
mechanisms work I> > would greatly appreciate it. Each mechanism is
relatively low weight, 16> > ounces or less but will have to deal
with significant wind forces while> > operating. If you have ideas
or need more information to figure this out> > please let me
know.> > > > Thanks so much,> > Jackson
Hennes